Molecular orientation of chiral paramagnetic liquid crystals under electric and/or magnetic fields

Noda, Yohei; Koizumi, Satoshi; Hashimoto, Takeji; Shimono, Satoshi*; Baba, Masaaki*; Yamauchi, Jun*; Ikuma, Naohiko*; Uchida, Yoshiaki*; Tamura, Rui*; Iima, Yoshio*

Recently, the chiral paramagnetic liquid crystals (LCs) were synthesized, whose spin sources are fixed in their rigid core. Their responses to an electric and magnetic fields are attractive topics. In general, LC molecules align with the rubbing direction on the oriented film of the LC cell. By far, by use of this surface stabilization effect on LC cell surface, we have developed this potential method of the EPR measurement with rotating the oriented LC cell sample. More recently, the chiral paramagnetic LC showing ferroelectricity was synthesized. We will report the EPR investigation of the orientation change of the ferroelectric LC in response to the switching of an applied electric field. It was shown by the EPR measurement that with no electric field, the LC molecules directed nearly uniformly along the rubbing direction on the cell surface, on the other hand, with electric field (24V), the LC molecules largely tilted from the normal line of the smectic layer.